As well known to those skilled in the art, the property of every substance is determined by the bonding of component atoms, in which the bonding is carried out by outer electrons bound to the atoms. Changing the bonding status of a substance with electron beams of a sufficient energy level can obtain a property totally different from the previous one can be realized.
That is, electron beams may be irradiated to a substance to give an additional available property to it or to remove any property, for example, harmful to the human from it.
A cathode material used in an electron beam irradiator to generate electron beams is generally selected from various single crystals, oxides and so on that has a low work function. However, these materials are restricted in their size to use an e-beam irradiator sources, and thus the use of an electromagnet is necessary in order to give electron beams irradiation and treatment to an object in a wide area.
Besides, conventional electron beam irradiators are of thermoelectric actuation type in which a cathode material is heated with a filament up to a suitable high temperature in order to produce electron beams. This as a result essentially needs an additional separate power supply to be used together with the filament.